feat(cmakev2): Added multi_binary example for cmakev2

This commit adds a new example at
examples/build_system/cmakev2/features/multi_binary to
demonstrate the cmakev2 ability to build multiple binaries in a single
CMake project.

examples/build_system/cmakev2/README.md

@@ -167,6 +167,21 @@ Demonstrates the use of the Kconfig configuration system to conditionally includ
 
 **When to use:** When you need to build applications or components that must conditionally depend on other components based on `sdkconfig` options.
 
+---
+
+### multi_binary
+**Location:** [multi_binary](./features/multi_binary/)
+
+Demonstrates building multiple independent firmware binaries from a single project in one build command.
+
+**Build:** `idf.py build` creates both `app1.bin` and `app2.bin`
+**Flash App1:** `idf.py app1-flash monitor`
+**Flash App2:** `idf.py app2-flash monitor`
+
+**Key Concepts:** `idf_build_executable()`, `idf_build_binary()`, `idf_flash_binary()`, conditional component linking, Kconfig integration, multiple entry points
+
+**When to use:** Creating firmware variants with different features, manufacturing test firmware, or developing modular applications with compile-time configurable behavior.
+
 ## Build System v2 API Quick Reference
 
 ### Project Setup

examples/build_system/cmakev2/features/multi_binary/CMakeLists.txt

@@ -0,0 +1,54 @@
+cmake_minimum_required(VERSION 3.22)
+
+include($ENV{IDF_PATH}/tools/cmakev2/idf.cmake)
+
+project(multi_binary C CXX ASM)
+
+# Manual initialization for fine-grained control over component inclusion
+idf_project_init()
+
+# Build the first executable: app1
+# Links: app1_main, component1, component2
+idf_build_executable(app1.elf
+                     COMPONENTS app1_main component1 component2)
+
+# Build the second executable: app2
+# Links: app2_main, component1, component2, component3
+idf_build_executable(app2.elf
+                     COMPONENTS app2_main component1 component2 component3)
+
+# Generate binaries and flash targets
+
+# App1 binary
+idf_build_binary(app1.elf
+                 OUTPUT_FILE "${CMAKE_BINARY_DIR}/app1.bin"
+                 TARGET app1_binary)
+
+idf_flash_binary(app1_binary
+                 TARGET app1-flash
+                 NAME "app1"
+                 FLASH)
+
+# Generate metadata only for the primary app1 binary
+idf_build_generate_metadata(BINARY app1_binary)
+
+# Create menuconfig and confserver targets for app1 binary
+idf_create_menuconfig(app1.elf TARGET app1-menuconfig)
+idf_create_confserver(app1.elf TARGET app1-confserver)
+
+# App2 binary
+idf_build_binary(app2.elf
+                 OUTPUT_FILE "${CMAKE_BINARY_DIR}/app2.bin"
+                 TARGET app2_binary)
+
+idf_flash_binary(app2_binary
+                 TARGET app2-flash
+                 NAME "app2"
+                 FLASH)
+
+# Create menuconfig and confserver targets for app2 binary
+idf_create_menuconfig(app2.elf TARGET app2-menuconfig)
+idf_create_confserver(app2.elf TARGET app2-confserver)
+
+# Make both binaries part of the default "app" target
+add_custom_target(app ALL DEPENDS app1.bin app2.bin)

examples/build_system/cmakev2/features/multi_binary/README.md

@@ -0,0 +1,92 @@
+| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-C61 | ESP32-H2 | ESP32-H21 | ESP32-H4 | ESP32-P4 | ESP32-S2 | ESP32-S3 |
+| ----------------- | ----- | -------- | -------- | -------- | -------- | --------- | -------- | --------- | -------- | -------- | -------- | -------- |
+
+# Multi-Binary Example: Multiple Apps with Different Component Sets
+
+This example demonstrates **Build System v2's** capability to build multiple independent firmware binaries from a single project in one build command. Each binary has its own entry point component with different dependencies.
+
+## Overview
+
+Two independent executables are built simultaneously:
+
+1. **`app1.bin`** - Links `app1_main`, `component1`, `component2`
+2. **`app2.bin`** - Links `app2_main`, `component1`, `component2`, `component3`
+
+Each app has its own dedicated entry point component that explicitly declares which components it needs. This avoids complex conditional logic and makes dependencies clear.
+
+## Project Structure
+
+All components live under `components/`. Each `idf_build_executable` call picks exactly the subset it requires.
+
+```
+multi_binary/
+├── CMakeLists.txt
+└── components/
+    ├── app1_main/      # Entry point for app1
+    │   ├── CMakeLists.txt
+    │   └── app1_main.c
+    ├── app2_main/      # Entry point for app2
+    │   ├── CMakeLists.txt
+    │   └── app2_main.c
+    ├── component1/     # Shared component
+    │   ├── CMakeLists.txt
+    │   ├── component1.c
+    │   └── component1.h
+    ├── component2/     # Shared component
+    │   ├── CMakeLists.txt
+    │   ├── component2.c
+    │   └── component2.h
+    └── component3/     # Only linked into app2
+        ├── CMakeLists.txt
+        ├── component3.c
+        └── component3.h
+```
+
+## Building
+
+### Build both binaries in a single command:
+
+```bash
+cd examples/build_system/cmakev2/features/multi_binary
+idf.py set-target <target> 
+idf.py build
+```
+
+This generates both `app1.bin` and `app2.bin` in the `build/` directory.
+
+## Flashing
+
+Flash app1:
+```bash
+idf.py app1-flash monitor
+```
+
+Flash app2:
+```bash
+idf.py app2-flash monitor
+```
+
+You can switch between apps without rebuilding - just select which one to flash.
+
+### Configuration (menuconfig)
+
+When invoking a custom menuconfig target via `idf.py`, you must pass `--no-hints`. For example, use `idf.py app1-menuconfig --no-hints` (plain `idf.py app1-menuconfig` may not work because `idf.py` redirects stdout by default, which breaks the curses-based menu).
+
+> **Note:** Although multiple binaries can be produced from a single project, each component is evaluated only once using the current configuration. If a different configuration is needed for a component, a new project must be created. You cannot use the same component with different configurations within a single project.
+
+## Expected Output
+
+### app1 Output
+
+```
+I (xxx) component1: Hello from component1!
+I (xxx) component2: Hello from component2!
+```
+
+### app2 Output
+
+```
+I (xxx) component1: Hello from component1!
+I (xxx) component2: Hello from component2!
+I (xxx) component3: Hello from component3!
+```

examples/build_system/cmakev2/features/multi_binary/components/app1_main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "app1_main.c"
+                       PRIV_REQUIRES component1 component2)

examples/build_system/cmakev2/features/multi_binary/components/app1_main/app1_main.c

@@ -0,0 +1,22 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include "sdkconfig.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "component1.h"
+#include "component2.h"
+
+void app_main(void)
+{
+    component1_print_hello();
+    component2_print_hello();
+
+    while (1) {
+        vTaskDelay(pdMS_TO_TICKS(10000));
+    }
+}

examples/build_system/cmakev2/features/multi_binary/components/app2_main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "app2_main.c"
+                       PRIV_REQUIRES component1 component2 component3)

examples/build_system/cmakev2/features/multi_binary/components/app2_main/app2_main.c

@@ -0,0 +1,24 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include "sdkconfig.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "component1.h"
+#include "component2.h"
+#include "component3.h"
+
+void app_main(void)
+{
+    component1_print_hello();
+    component2_print_hello();
+    component3_print_hello();
+
+    while (1) {
+        vTaskDelay(pdMS_TO_TICKS(10000));
+    }
+}

examples/build_system/cmakev2/features/multi_binary/components/component1/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "component1.c"
+                       INCLUDE_DIRS ".")

examples/build_system/cmakev2/features/multi_binary/components/component1/component1.c

@@ -0,0 +1,15 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include "esp_log.h"
+
+static const char *TAG = "component1";
+
+void component1_print_hello(void)
+{
+    ESP_LOGI(TAG, "Hello from component1!");
+}

examples/build_system/cmakev2/features/multi_binary/components/component1/component1.h

@@ -0,0 +1,12 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef COMPONENT1_H
+#define COMPONENT1_H
+
+void component1_print_hello(void);
+
+#endif // COMPONENT1_H

examples/build_system/cmakev2/features/multi_binary/components/component2/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "component2.c"
+                       INCLUDE_DIRS ".")

examples/build_system/cmakev2/features/multi_binary/components/component2/component2.c

@@ -0,0 +1,15 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include "esp_log.h"
+
+static const char *TAG = "component2";
+
+void component2_print_hello(void)
+{
+    ESP_LOGI(TAG, "Hello from component2!");
+}

examples/build_system/cmakev2/features/multi_binary/components/component2/component2.h

@@ -0,0 +1,12 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef COMPONENT2_H
+#define COMPONENT2_H
+
+void component2_print_hello(void);
+
+#endif // COMPONENT2_H

examples/build_system/cmakev2/features/multi_binary/components/component3/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "component3.c"
+                       INCLUDE_DIRS ".")

examples/build_system/cmakev2/features/multi_binary/components/component3/component3.c

@@ -0,0 +1,16 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include "esp_log.h"
+#include "sdkconfig.h"
+
+static const char *TAG = "component3";
+
+void component3_print_hello(void)
+{
+    ESP_LOGI(TAG, "Hello from component3!");
+}

examples/build_system/cmakev2/features/multi_binary/components/component3/component3.h

@@ -0,0 +1,12 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef COMPONENT3_H
+#define COMPONENT3_H
+
+void component3_print_hello(void);
+
+#endif // COMPONENT3_H